Pteris cretica
Common name
Cretan brake
Family
Pteridaceae
Flora category
Vascular – Exotic
Structural class
Ferns
Conservation status
Not applicable
Distribution
Naturalised. New Zealand: North and South Islands (widespread from Whangarei south to Banks Peninsula). Indigenous to to the warm-temperate and tropical parts of the Old World.
Habitat
Coastal to montane (mostly coastal to lowland). A common weedy fern in many urban parts of New Zealand but also common in less modified areas growing in dense forest, along river, stream and gully banks, on track and roadside cuttings. It can be very common in wasteland areas within cities and towns, and often appears on retaining walls, and even under houses (provided there is some light).
Features
Large terrestrial ferns. Rhizome short-creeping; scales minute, dark brown. Fronds dimorphic, clustered. Stipes 0.25-0.9 m long, yellow-brown, glabrous. Lamina 0.2-0.6 × 0.1-0.4 m, dark green (occasionally variegated) broadly oblong to oblong, 1-pinnate, often incompletely 2-pinnate (forked) at the base; primary pinnae in 2-7 widely spaced pairs, somewhat ascending, narrowly lanceolate, linear to linear-falcate, tapering to apices and long-acuminate with smooth or minutely denticulate margins, chartaceous, glabrous; rachis not winged or slightly winged at apex. Lower pinnae short-stalked, in mature plants with 1-3 posterior short-stalked free conform pinnules. Upper pinnae sessile, uppermost adnate to rachis. Terminal pinna slightly contracted; apex of sterile pinna, sharply dentate. Veins free, simply or once-forked; false veins absent. Sori continuous; indusium subentire; paraphyses numerous.
Similar taxa
Easily distinguished from all indigenous and naturalised Pteris except P. pacifica by the 1-pinnate fronds bearing long, narrow-lanceolate, linear to linear-falcate pinnae, with the basal few pairs often forked. From the very uncommon P. pacifica, P. cretica is readily distinguished by the typically dark green rather than yellow-green fronds, and by the distal portion of the sterile pinnae margins sharply dentate. Pteris cretica could be confused with P. vittata however that species has a much narrower frond, with a distinctly longer terminal pinna, and by the pinnae which are never forked and which reduce in size toward the frond base.
Flowering
Not applicable - spore producing
Flower colours
No flowers
Fruiting
Not applicable - spore producing
Propagation technique
Pteris cretica is commonly cultivated and exists in a diverse range of forms which include the usually dark green plants, as well as variegated ones and those whose pinnae apices are much divided (i.e. “crested”). It is an aggressive fern that rapidly spreads and probably should not be cultivated anymore as it rapidly spreads from garden environments into indigenous habitats, especially coastal and lowland forest, along river, stream, and gully sides, and even wetlands. Pteris cretica is remarkably tolerant of a range of conditions but does best when planted in a semi-shaded to shaded site in a deep, humus enriched, moist soil.
Year naturalised
1881
Origin
Tropics and temperate regions
Etymology
pteris: A fern known to the ancient Greeks; from the Greek pteris
References
Brownsey, P.J.; Smith-Dodsworth, J.C. 2000: New Zealand Ferns and Allied Plants. Auckland, David Bateman.
Kramer, K.U.; McCarthy, P.M. 1998: Pteridiaceae. Pp. 241-248. Flora of Australia 48. Australian Biological Resources Study, CSIRO Canberra
Fact Sheet Prepared for NZPCN by: P.J. de Lange (18 January 2012). Description adapted from Brownsey & Smith-Dodsworth (2000) and Kramer & McCarthy (1998)